In most organizations there is a frequent need to communicate with others within the organization. When trying to reach a person, the person initiating the communication (an initiating end user) often wants to communicate in a manner (or mode of communication) that has the best probability of reaching the targeted individual. Further, since day-to-day schedules are usually busy and targeted individuals may frequently be in meetings, the initiating end user may want the communication to be minimally intrusive with respect to a targeted end user.
Unfortunately, without intimate knowledge of the day-to-day schedule of the targeted end user, the person initiating the communication may not know the best mode of communication to use in reaching the targeted end user.